Square Enix has trademarked the name Mini Ninjas: Hiro's Adventure and registered related website domains such as minininjahirosadventure.com.
Siliconera spotted them, but is none the wiser about what they refer to.
Mini Ninjas was the friendly cartoon action game made by Hitman and Kane & Lynch developer IO Interactive.
Right now, IO is making Hitman: Absolution for release this year. And after that, IO apparently wants to make new IP, presumably to launch on a new generation of consoles.
So what is Mini Ninjas: Hiro's Adventure, if anything at all?
It's not the Google Chrome version, which launched this week.
"Square Enix does not comment on rumour and speculation," Eurogamer was told.